The Bologna Open Clusters
Chemical Evolution project
(BOCCE, in short)

Angela Bragaglia, Eugenio Carretta & Monica Tosi (INAF-OA Bologna),
     Michele Cignoni
(INAF-OA Bologna, and Dip.Astr.Univ.Bologna), Raffaele
Gratton (INAF-OA Padova), Gloria Andreuzzi & Luca Di Fabrizio
(INAF-Fundacion Galilei), Jason Kalirai (UCO-Lick), Gianni Marconi (ESO)

(plus fruitful collaborations with other collegues)

The BOCCE project is aimed at obtaining in the most homogeneous way the properties (age, distance, reddening, metallicity and detailed elemental abundances) of a sample of (mostly old) Galactic Open Clusters. A detailed description of our program and the results of the first part of the photometric survey can be found in Bragaglia & Tosi (2006).

The clusters observations can be divided in three parts:

(1) PHOTOMETRY : multiband optical CCD photometry (usually BVI)

(2) LOW-RED SPECTROSCOPY: multi object spectra to derive radial velocity and membership

(3) HIGH-RES SPECTROSCOPY:  to measure metallicity and detailed chemical composition

Age, distance, reddening and a first indication of metallicity are obtained using the synthetic colour-magnitude diagram technique (as developed in Tosi et al. 1991).  
Results of the first 20 OCs can be found in Table 1
The CMDs for the first 20 OCs can be seen here

High-res spectra (FEROS@1.5m ESO, UVES@VLT, SARG@TNG, with R=30000-48000) have been obtained for 3-6 red clump stars per cluster.  [Fe/H] and detailed metallcities for several clusters have been determined. See Table 2 for a list of the clusters already analyzed. 

MOS with LRS@TNG has been used to derve RVs of stars in key evolutionary phases (Be 29, Be 32, Be 17 done up to now)

A more complete list of the OCs in our sample can be found in Table 3


The list of papers related to the BOCCE project can be found here :  (link to publication list)

The Figure below indicates the position of the BOCCE clusters in the MW, with the Galactic Center at 0,0 and the Sun at 8 kpc from the center. The different colour/symbols indicate the advancement of the study of a particular cluster.
                Location of the BOCCE clusters in the MW

The Figure below  shows the histogram of ages and Galactocentric radii (Rgc) of OCs in the BOCCE sample (as in October 2007) and the radial metallicity gradient (symbols refer to different sources of data, all from the BOCCE project or from literature).                      

histogram of age, Rgc & radial metallcity gradient